Centralizing device



. Jan. 11, 1944. M D AR IN r 23395089 CENTRALIZING DEVICE Filed m 12,1942 INVENTORS MAW/N D. M4Pr/A/ KE NETH A. 5mm.

ATT RNEYS Patented Jan. 11, 1944 CENTRALIZING DEVICE Marvin D. Martin,Berkeley, and Kenneth A. Snell, Alameda, Calii'., assignors to MarchantCalculating Machine Company, a corporation of California Application May12, 1942, Serial No. 442,604

12 Claims.

This invention relate to rotary, cyclically operable calculatingmachines and the like, and has particular reference to improvements indevices for accurately locating rotatable elements thereof in definitecyclic positions as such elements come to rest after a single or amulticyclic operation of the machine. Such devices are commonly known ascentralizing devices.

The invention is preferably embodied in a centralizing device employedin connection with the actuator unit of a calculating machine, being animprovement on a device of the same general character which has beenused on the well known Marchant calculating machines and which isdisclosed in Figure 51 of the patent to Harold T, Avery Number2,216,659, issued October 1, 1940. Reference may be had to said patentfor a disclosure of a complete calculating machine including mechanismnot specifically described herein.

However, it is to be understood that the invention is not limited to usein connection with machines of this type or even to use in connectionwith a calculating machine, and that such variations may be made as arewithin the scope of the invention as set forth in the appended claims.

One object of the present invention is to reduce to a minimum the forcenecessary to operate a centralizing device of the present type.

Another object is to reduce the noise and wear incident to the operationof a centralizing device.

Another object is to permit a large tolerance in manufacturing limitsfor centralizing devices of the present typ A still further object is toprovide a simple, inexpensive, and quiet centralizing device capable ofcentralizing a cyclically operable mechanism either after a single cycleor after a multicyclic operation.

The centralizing device disclosed in the above mentioned Avery patent,although satisfactory in operation, produces a certain degree of noiseduring a multicyclic operation such as multiplication and division dueto the fact that when dimensional errors within ordinary manufacturingtolerances are present, the centralizing rollel's can not, be heldlocked in the position they occupy during contact with the concentricportion of the centralizing cam. A certain amount of clearance must bepermitted to allow the locking means to move into position to lock thecentralizers against movement into the notches of the cam. Therefore,each time the actuator passes full cycle position the centralizingrollers drop slightly into the depressions or notches of the cam and arecammed out again, causing a noticeable noise and vibration.

Other centralizing devices have been devised in the past in which thecentralizing rollers have actually been held out beyond the periphery ofthe concentric portion of the cam. However, these devices are relativelymore complicated and considerable force must be used to unlatch thesame, thereby requiring motor driven or at least relatively strongspring unlatching means.

The manner in which the above mentioned and other objects of theinvention are accomplished will be readily understood on reference tothe following specification when read in conjunction with theaccompanying drawing, wherein:

Figure 1 is an elevational view from the left hand side of a Marchantcalculating machine of the character disclosed in the aforesaid patent,illustrating the main clutch, the controls therefor, and the meansassociated with such controls I for controlling the centralizing devicefor the actuator.

Figure 2 is a sectional plan view of the centralizing device and istaken along the line 2-2 of Figure 3.

Figure 3 is a left side view of the device showing the same incentralizing position.

Figure 4 is a view'similar to that of Figure 3 showing the actuatorout'of full cycle position and the centralizing device out ofcentralizing position.

Figure 5 is a sectional plan view of the ad- Justable pivot support forthe centralizer arms and is taken along the line 5-5 of Figure 3.

Figure 6 is an enlarged schematic view illustrating details ofconstruction of the centralizing cam and roller wedging or disablinglever.

As described in detail in the above mentioned Avery patent the machineto which the mechanism of the present invention is applied hasincorporated therein a cyclically operable main clutch 428 driven by themachine motor (not shown). This clutch, when engaged, transmits rotationthrough gears 458 and 484 to an actuator shaft I66 forming part of theactuator unit. The ratio of the gearing between the main clutch and theshaft I66 is such that for each cycle of operation (one-half revolution)of the main clutch 428 the actuator shaft 66 is also operated throughone cycle (one-half revolution).

The main clutch 428 is controlled by a clutch dog 395 which is normallyspring urged, as shown in the above mentioned patent, into contact withnotches 424 formed on the periphery of the clutch to hold the clutchdisengaged. However, upon initiation of operation of the machine toperform a calculating function, the dog 395 is rocked counter-clockwiseout of contact with one of the clutch notches 424, enabling the clutchto engage and thereby drive the actuator shaft I66. Means are providedto hold the clutch dog 365 out of contact with the main clutch to causea multi-cyclic operation thereof during multiplication and division.This comprises a latch 632 pinned on a rockable shaft 626 and urgedcounter. clockwise by a tension spring 633 extending between the latchand the machine framework. The latch 632 has a roller 634 thereon whichis adapted to be positioned under an ear 626 formed on the dog 395.

When a multiplication or division operation involving multi-cyclicoperation of the main clutch is instituted, the spring 633 is allowed tohold the latch 632 against the ear 626 of the clutch dog and when thedog is thereafter rocked to engage the main clutch, the roller 634 ismoved to a position underlying the ear 626, thereby allowing the mainclutch to continue for the desired number of cycles, during the lastcycle of which the latch is automatically rocked clockwise to releasethe clutch dog. The clutch dog 395 may be released during any part ofthe last cycle of a multicyclic operation and will merely ride on thepe-- riphery of the clutch 426 until it seats in one of the notches 424.Release of the main clutch dog 395 by the latch 632 causes thecentralizing device to become effective to centralize the actuator shaftI66 as will presently appear.

The centralizing device comprises a centralizer cam I I keyed on theactuator shaft I66 and having a circular periphery provided with twodiametrically opposed depressions I2 formed thereon. The cam II isengaged by flanged centralizing rollers I3 and I4 rotatably mounted onstuds I3 and I4 (Figure 2), on the upper ends of arms l5 and I6,respectively. Both arms are pivoted on an adjustable frame-carried pinIT.

The rollers I3 and I4 are so arranged as to engage the opposite notchesI2 in the cam II when the shaft I66 is in centralized position, and topermit adjustment of the rollers to insure such engagement, the pivotpin II (Figures 3, 4, and 5) has the bearing portions IIa thereofarranged eccentric to the main portion III), the latter comprising athreaded stud extending through a slot I9 in the left machine frameplate 26 and secured in adjusted position therein by a clamp nut 2Ia.Also, the curved slot I9 is concentric with the actuating shaft I 66 sothat the rollers I3 and I4 may be adjusted in position about the cam IIto compensate for any errors due to angular misalignment of the cam IIon actuator shaft I66.

A tension spring 2| is extended between the arms I5 and I6, and when themachine is at rest (as illustrated in Figures 1 and 3), the spring iseffective to hold the rollers I3 and I4 in the depressions I2 of cam IIand thus hold the shaft I66 accurately located in full cycle position.The provision of the two arms I 5 and I6 and rollers I3 and I4 providesa better centralizing action than a single arm and roller would provideand also results in a much lower load on the bearing 35 (Figure 2) forshaft I66 than would be the case if only a single arm and roller wereused.

Means are provided for preventing the spring 2| from forcing the rollersI3 and I4 into the notches l2 when the shaft I 66 passes full cycleposition during continuous multicyclic operation and thereby eliminatesthe noise and wear which would otherwise result therefrom. .As'shown inFigures 2, 3, and 4 a roller wedging or disabling lever 23 is disposedadjacent the cam II and has a bearing portion pivotally mounted onthehub II of the cam II. The lever 23 has diametrically opposed raisedportions 25 which are adapted, upon clockwise rocking movement of thelever 23 10 from its position illustrated in Figure 3 and after therollers I3 and I4 have been cammed outward by the cam I I, to contactrollers-26 and 21 mounted on the studs I3 and I4 concentrically with therollers I3 and I4, respectively, and thereby hold the rollers I3 and I4in their outer positions illustrated in Figure 4, overcoming the actionof spring 2|. It should be noted that the diameters of rollers 26 and 21are identical with the diameters of rollers I3 and I4.

The position of the lever 23 is controlled by the main clutch dog 395(Figure 1) in the following manner. Suitably secured to the dog is anear 625 engaged by the camming nose 663 of an arm 662 which is rigidlyconnected by a rockable 25 shaft 66I to a second arm 666, the latterbeing engaged by an ear 26 of a bell crank 26 pivoted on the frame pin3| and urged counter-clockwise against the arm 660 by a tension spring36 extending between the bell crank 29 and the machine frame.

The ,3. crank 29 is bifurcated at its left hand end to embrace a pin 32extending from the roller disabling lever 23 so that when the mainclutch dog 395 is spring moved to clutch disengaging position(illustrated in Figure 1), the dog will rock the arms 662 and 660counter-clockwise, transmitting movement through the bell crank 29 torock the wedging lever 23 counterclockwise to the position illustratedin Figure 3 wherein the raised portions 25 will be moved away from underthe rollers 26 and 21. Therefore, the spring 2I may become effective tomove the rollers into the notches I2 of cam II or to press the rollersagainst the periphery of the cam II in the event that the shaft I66 hasnot yet reached full cycle position.

When the main clutch dog 395 is rocked counter-clockwise to causeengagement of the main clutch, the ear 626 thereon will be movedupwardly, passing considerably above the upper surface of the cammingnose 663, so that the arm 662 will be released to allow the spring 39 tobecome effective to rock the bell crank 29 and the roller wedging lever23 to their disabling position which is approximately that illustratedin Figure 4, but which may vary slightly as will appear hereinafter. Atthis time the main clutch will operate causing rotation of the shaft I66 and the cam II, and the latter will cam the rollers I3 and I4outwardly until they ride on the concentric portion thereof. The spring36 is therefore allowed to rock the lever 29 and roller wedging lever 23to a position wherein the raised portions 25 of lever 23 contact therollers 26 and 21. Since the radial dimension measured between theopposite contacting points of the raised portions 25, is the same as thediameter of the concentric portions of the cam II, as will be explainedin detail presently, the actuator shaft I66 may pass its full cycleposition without entry of the rollers I3 and I4 into the centralizingnotches I2 of the cam II. During the last cycle of operation of the mainclutch, the clutch dog 395 is permitted to be rocked against theperiphery of the main clutch 426 under a spring pressure which isstronger than that of spring 30 and, as before stated, forces the arms662 and 660 to rock the bell crank 29 and lever 23 into their positionsillustrated in Figure 3. Now, as the actuator shaft I66 reaches fullcycle position the spring 2| will be allowed to force the rollers I3 andI4 into the notches I2 to centralize the actuator unit.

Referring to the enlarged schematic view in Figure 6, it will be seenthat the center C1 of the radius R of the raised portion 25 on lever 23is not coincident with the center C of the cam II and shaft I66, but issomewhat offset therefrom, with the result that the raised portions 25form wedging or camming surfaces.

Theoretically, the center C1 should be sosplaced that the periphery ofthe raised portion 25 intersects the periphery of the cam I I at a pointmidway between the limits of the arcuate raised portion 25 as defined bythe dimension S. However, due to allowances for manufacturingtolerances, this intersection may, in actual practice, be situated aboveor below such midway point without in any way affecting the operation ofthe device. That is, if the point of intersection were above the midwaypoint the spring 30 would merely rock the bell crank 29 and lever 23somewhat further to contact therollers 26 and 21 than would be the caseif the point of intersection were below such midway point. In eithercase, however, the raised portions 25 would prevent even a slight dropof the rollers I3 and I4 into the notches I2 of the cam II during amulti-cyclic operation of the actuator. It should, therefore, be notedthat the center C1 should be so displaced relative to the center C that,within the range of possible variations in dimensions of the cam II andlever 23 due to the usual tolerance in manufacturing limits, the raisedportions 25 will contact the rollers 26 and 21 somewhere along thelength S thereof.

Lobes 30a are formed on the lever 23 adjacent the higher ends of theraised portions 25 to limit against the rollers 26 and 21 in thepossible event that the raised portions 25 contact the rollers at theirhighest points.

The relationship between the strength of spring 2 I and spring 30 ispreferably such that the spring 30 is ineffective to cause the rollerwedging lever 23 to cam the arms I and I6 outward of its own accord.Also, in practice, it has been found preferable to arrange the center C1so that radial lines passing through the centers C and Cl, andintersecting at the theoretical intersection of the surfaces of theconcentric portion of cam II and the raised portion 25, form an angle ofapproximately 3. This angie has been found suflicient to enable therelatively heavy spring 2I to hold the rollers I3 and I4 against theconcentric portions of the periphery of the cam II, against the urge ofspring 30, but is insufficient to allow the spring 2I to cause therollers 26 and 21 to cam the wedging lever 23 counterclockwise of itsdisabling position shown in Figure 4 during passage of the notches I2 incam II past the rollers I3 and I4 at the normal operating speed of themachine and, therefore, the rollers I3 and I4 cannot enter thedepressions I2 at this time. Furthermore, the above camming angle issuch as to allow the spring 2I to tend to aid the spring urged clutchdog 395 in forcing the arms 662, 660, bell crank 29 and wedging lever 23toward their disabling positions of Figures 1 and 3 at the end of asingle or multicyclic operation.

As a modification of the preferred embodiment of the invention andoperation thereof, the

spring 30 may be replaced by a stronger spring which would be strongenough to always cause the lever 23 to cam the rollers I3 and I4entirely- 5 out of contact with the concentric portions of the cam IIduring operation of the main clutch. In this event, the lobes 30a wouldalways limit against the rollers 26 and 21.

We claim: I

1. In a cyclically operable mechanism of the character describedincluding a rotatable cam having a high portion and a low portion; thecombination with control means for initiating operation of saidmechanism and for terminating l6 operation thereof; of a centralizingmember spring urged into engagement with said cam, a

wedging member movable into wedging engagement with said centralizingmember to maintain the same at any position to which it is moved by saidcam upon rotation thereof, and means responsive to said control meansupon termination of operation of said mechanism thereby for moving saidwedging member out of engagement with said centralizing member.

2. In a cyclically operable mechanism of' the character describedincluding a rotatable cam having a high portion and a low portion; thecombination with control means for initiating operation of saidmechanism and for terminating operation thereof; of a centralizingmember spring urged into engagement with said cam, a

wedging member pivotally supported for rocking movement through alimited angle about the axis of rotation of said cam and rockable intowedging engagement with said centralizing member to maintain the same atany position to which it is moved by said cam upon rotation thereof, andmeans responsive to said control means upon termination of operation ofsaid mechanism 40 thereby for rocking said wedging member out ofengagement with said centralizing member.

3. In a cyclically operable mechanism of the character describedincluding a rotatable cam having a high portion and a low portion; thecombination with control means for initiating operation of said me'hanism and for terminating operation thereof; of a centralizing memberspring urged into engagement with said cam, a wedging member movableinto wedging engagement with said centralizing member to maintain thesame out of engagement with the low portion of said cam, meanscomprising a spring for moving said wedging member into engagement withsaid centralizing member, said last named means being incapable ofcausing said wedging member to move said centralizing member out ofengagement with the high portion of said cam, and means responsive tosaid control means upon termination of operation of said mechanismthereby for moving said wedging member out of engagement with saidcentralizing member.

4. In a cyclically operable mechanism of the character describedincluding a rotatable cam having a high portion and a low portion. thecombination with control means for initiating operation of saidmechanism and for terminating operation thereof; of a centralizingmember spring urged into engagement with said cam, a wedging memberpivotally supported for movement about the axis of rotation of said camand rockable into wedging engagement with said centralizing member tomaintain the same out of engagement with the low portion of said cam,means comprising a spring for rocking said wedging member intoengagement with said centraliz ing member, said last named means beingincapable of causing said wedging member to move said centralizingmember out of engagementwith the high portion of said cam, and meansresponsive to said control means upon termination of operation of saidmechanism thereby for rocking said wedging member out of engagement withsaid centralizing member.

5. In a cyclically operable mechanism of the character describedincluding a rotatable cam,

having opposed low portions, the .combination with control means forinitiating operation of said mechanism and for terminating operationthereof; of spring urged centralizing members for concomitantly engagingsaid low portions, 9. wedging member pivotally supported for moyementabout the axis of rotation of said cam and ockable into wedgingengagement with said centralizing members to maintain the same out ofengagement with the low portions of said cam, means comprising a springfor rocking said wedging member into engagement with said centralizingmembers, said spring means being incapable of causing said wedgingmember to move said centralizing members out of engagement with saidcam, and means responsive to saidcontrol means upon termination ofoperation of said mechanism thereby for rocking said wedging member outof engagement with said centralizing member.

6. In a cyclically operable mechanism of the character describedincluding a cyclic clutch; a control member therefor movable to clutchengaging and disengaging positions, and a rotatable cam driven by saidclutch and having a high portion and a low portion; the combination of acentralizing member spring urged into engagement with said cam, awedging member movable into wedging engagement with said centralizingmember to maintain the same at any position to which said member ismoved by said cam upon rotation thereof, and means responsive to saidcontrol member upon movement thereof to clutch disengaging position formoving said wedging member out of engagement with said centralizingmember.

7. In a cyclically operable mechanism of the character describedincluding a cyclic clutch, a control member therefor movable to clutchengaging and disengaging positions; and a rotat-"' able cam driven bysaid clutch and having a high portion and a low portion; the combinationof a centralizing member spring urged into contact with said cam, awedging member movable into wedging engagement with said centralizingmember to maintain the same out of engagement with the low portion ofsaid cam, means including a spring for moving said wedging member intoengagement with said centralizing member, said means being incapable ofcausing said wedging member to move said centralizing member out ofengagement with said cam, and means responsive to said control memberupon movement thereof to clutch engaging position for causing operationof said first named means, said last named means being responsive tosaid control member upon movement thereof to clutch disengaging positionfor moving said wedging member out of engagement with said centralizingmember.

8. In a cyclically operable mechanism of the character describedincluding a cyclic clutch, a control member therefor movable to clutchengaging and disengaging positions, and a rotatable cam driven by saidclutch and having a high portion and a low portion; the combination of acentralizing member spring urged into contact with said cam, a wedgingmember pivotally supported for movement about the axis of rotation ofsaid cam and rockable into wedging engagement with said centralizingmember to maintain the same out ofengagement with the low portion ofsaid cam, means including a spring for rocking said wedging member intoengagement with said centralizing member, said spring means beingincapable of causing said wedging member to move said centralizingmember out of engagement with said cam, and means responsive to saidcontrol member upon movement thereof to clutch engaging position forcausing operation of said first named means, said last named means beingresponsive to said control member upon movement thereof to clutchdisengaging position for rocking said wedging member out ofengagement'with said centralizing member.

9. In a cyclically operable mechanism of the character describedincluding a rotatable cam having a high portion and a low portion; thecombination with control means for initiating operation of saidmechanism and for terminating operation thereof of a centralizing memberspring urged into engagement with said cam, a wedging member movableinto wedging ngagement with said centralizing member to maintain thesame at any position to which said member is moved by said .cam uponrotation thereof, and means responsive to said control means uponinitiation of the operation of said mechanism thereby for moving saidwedging member into engage.- ment with said centralizing member; saidlast named means being responsive to said control means upon terminationof the operation of said mechanism thereby for moving said wedgingmember out of engagement with said centralizing member. l

10. In a cyclically operable mechanism of the character describedincluding a rotatable cam having a high portion and a low portion; the

combination with control means for initiating operation of saidmechanism and for terminating operation thereof; of a centralizingmember spring urged into engagement with said cam, a non-rotatablewedging member pivotally supported for rocking movement about the axisof rotation of said cam and rockable into wedging engagement with saidcentralizing member to maintain the same at any position to which saidmember is moved by said cam upon rotation thereof, and mean responsiveto said control means upon initiation of the operation of said mechanismthereby for rocking said wedging member into engagement with saidcentralizing member; said last named means being responsive to saidcontrol means upon termination of the operation of said mechanismthereby for rocking said wedging member out of engagement with saidcentralizing member.

11. In a cyclically operable mechanism of the character describedincluding a rotatable cam having a high portion and a low portion; thecombination with control means for initiating operation of saidmechanism and for terminating operation thereof; of a centralizingmember spring urged into engagement with said cam, a wedging membermovable into engagement with said centralizing member so as to engagethe centralizing member at a camming angle less than the angle offriction effective between said two members, and means responsive tosaid contralizing member at a camming angle less than the angle 01'friction en'ective between said two members, and means responsive tosaid control means upon initiation of operation of said mechanismthereby for moving said wedging member into engagement with saidcentralizing member, said last named means being incapable of causingsaid wedging member to move said centralizing member out of engagementwith the high operation thereof; of a, centralizing member 10 portion ofsaid cam.

spring urged into engagement with said cam. a wedging member movableinto engagement with said centralizing member so as to engage the cen-MARVIN D. MARTIN. KENNETH A. SNELL.

